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Installation, commissioning and operating instructions for valve-regulated stationary lead-acid batteries
7140203153 V1.4 (09.2018)
Installation, commissioning and operating instructions for valve-regulated stationary lead-acid batteries
7140203153 V1.4 (09.2018)
7.4 Influence of cycling on battery behavior
7.4.1 Endurance in cycles depending on depth of discharge
The endurance in cycles is defined as number of discharging and charging cycles until the actual remaining
battery capacity drops below 80% of the nominal capacity (C
10
). The endurance in cycles of a lead acid battery
is directly depending on the regular depth of discharge (DoD) during these cycles. Depending on different types
of batteries and the design of the plates and electrodes, the endurance in cycles may vary significantly.
The following chart
(refer to fig. 7–8)
shows the cycling behavior of a HOPPECKE
sun
| power
VR L
(OPzV solar.power/OPzV bloc solar.power) under ideal operating conditions. The cycle life refers to one dischar-
ge per day. Endurance in cycles cannot exceed stated service life under float charge conditions.
Fig. 7–8: Endurance in cycles of
sun
| power
VR L
(OPzV solar.power) as a function of DoD (at 20 °C)
7.4.2 Endurance in cycles depending on ambient temperature
Since design life mainly depends on temperature, the cycle lifetime is affected by temperature as well.
Fig. 7-9
depicts this relation for a regular battery depth of discharge of 80 %.
Fig. 7–9: Endurance in cycles of
sun
| power
VR L
(OPzV solar.power) as a function of ambient temperature
Cycle Number [n]
Depth of Discharge DoD [%]
Cycles [n]
Ambient Temperature in °C
7.3 Temperature influence on battery performance and service life
7.3.1 Temperature influence on battery capacity
Battery capacity depends significantly on ambient temperature. Lead acid batteries loose capacity with decre-
asing temperature and vice versa, as shown in
fig. 7-6
. This should be considered when sizing the battery.
Temperature range for
sun
| power
VR L
(OPzV solar.power/OPzV bloc solar.power) batteries:
Possible temperature range:
-20 °C to 45 °C
Recommend temperature range:
15 °C to 35 °C
Fig. 7–6:
sun
| power
VR L
(OPzV solar.power/OPzV bloc solar.power): Dependency of battery capacity on temperature
7.3.2 Temperature influence on battery service life
As corrosion processes in lead acid batteries are significantly depending on battery temperature, the battery
service life is directly related to the ambient temperature.
As rule of thumb it can be stated that the speed of corrosion doubles per 10 K increase (rule by Arrhenius).
Thus battery service life will be halved in case the temperature rises by 10 K.
The following graph
(refer to fig. 7–7)
shows this relationship. The diagram depicts operation in float charge
mode. Additionally, the endurance in cycles has to be taken into account.
Fig. 7–7: Service life of s
un
| power
VR L
(OPzV solar.power) cell as a function of ambient temperature (standby
application in float charge operation with 2.25 V/cell)
Service life in %
Ambient Temperature in °C
Temperature in °C
Battery Capacity in %
